If you want to create a HyperLinks in the GridView , so that if the user click on one link the outlock (or email client) will be opened and carry the clicked email ?
If we assumed that the User Email is stored in a column called "Email" , then you can use the following Column inside the GridView or any other Data Control:
<asp:TemplateField HeaderText="EMail" SortExpression="EMail">
<ItemTemplate>
<asp:HyperLink ID="HyperLink1" runat="server"
NavigateUrl='<%# Eval("EMail", "mailto:{0}") %>' Text='<%# Eval("EMail") %>'></asp:HyperLink>
</ItemTemplate>
</asp:TemplateField>